Clearance Measurements

1. Measure the journal outside diameter as shown in the illustration. Refer to Crankshaft Specifications.

NOTE: The crankshaft journals should be checked for excessive wear, taper and scoring. Limits of taper or out-of-round on any crankshaft journals should be held to 0.025 mm (0.001 inch). Journal grinding should not exceed 0.305 mm (0.012 inch) under the standard journal diameter. DO NOT grind thrust faces of Number 2 main bearing. DO NOT nick crank pin or bearing fillets. After grinding, remove rough edges from crankshaft oil holes and clean out all passages.

CAUTION: Forged steel crankshafts require that the final paper or cloth polish after any journal regrind be in the same direction as normal rotation in the engine.

2. Remove oil from journal and bearing shell.
3. Install crankshaft.





4. Cut plastigage to same length as width of the bearing and place it in parallel with the journal axis.
5. Install the main bearing cap carefully and tighten the bolts to specified torque.

CAUTION: Do not rotate crankshaft or the plastigage will be smeared.

6. Carefully remove the bearing cap and measure the width of the plastigage at the widest part using the scale on the plastigage package. Refer to Crankshaft Specifications for proper clearances. If the clearance exceeds the specified limits. Replace the main bearing(s) and if necessary have the crankshaft machined to next undersize. Also see Measuring Main and Connecting Rod Bearing Clearance in Standard Service Procedures.